Currently, more commonly used file encrypting methods are: direct encryption, transparent file encryption, and the encryption interface provided by the operating system. These three encryption methods are all capable of achieving file encryption; however, each of them has its own shortcomings described as follows.
Direct encryption is used to directly encrypt files in the disk, and WinRar™ is a typical representative. However, the shortcoming of direct encryption is: encrypted files should be manually decrypted every time before using the files, and also the decrypted files need to be manually encrypted after using. This method heavily depends on manual operation and the whole procedure is complex and cumbersome.
Transparent file encryption uses filter driver of an operating system (i.e. Window™) to encrypt/decrypt files, which overcomes the shortcoming of direct encryption that the files should be manually encrypted/decrypted. However, transparent file encryption still has the shortcoming that the filter driver of Windows exists on the file system driver of Windows. As a result, it is necessary to take a lot of filtering operations to all the files if the filter driver is used, and these filtering operations seriously affect system performance.
According to the above description, an urgent problem need to be solved provides a reliable, safe and effective file encrypting method.